Pullout switch



Oct. 6, 1959 H. H. KOBRYNER 2,907,849

PULLOUT SWITCH Filed Dec. 2o, 1956 2 sheets-sheet 2 INVEN TOR. l-/E/MA N H. KOBB YNER BY Z g ga( ATTORNEY United States Patent PULLOUT SWITCH Herman H. Kobryner, Forest Hills, N.Y., assignor to Murray Manufacturing Corporation, Brooklyn, N Y.

Application December 20, 1956, Serial No. 629,547

7 Claims. (Cl. 200-119) This invention relates to pullout switches.

More specifically, this invention relates to pullout switches of the type comprising essentially two parts. 'Ille first part consists of a base which is mounted, for example, to a Wall, and includes line and load terminals, and a pair of switch clips connected respectively to such terminals. The second part is called the puller and comprises a handle mounted on a cover, fuse, fuse holder and switch blades. The pullout switch closes the circuit when the switch blades are inserted into the clips connected to the line and load terminals. To state it another way, the pullout switch closes the circuit when the'puller portion is fully seated on the base portion.

This type of switch has been for some time, in wide use, particularly as entrance switches for residences. Service entrance equipments using this type of switch are generally available in a Wide variety of load capacities for the protection of different types of load circuits. Although a large portion of such switches required in these devices are of 60` ampere capacity, there is also need for many rated at only 30 amperes. These latter, for example, are used on major appliances requiring 2 or 3 wire, 240 volt supply, yat currents of 30 amperes or less. Typical of such appliances are, water heaters, laundry idriers, ironers, etc. Each of these major appliances is required by the Underwriters Code to be provided with separate fuse, disconnect switch and wiring. Thus, many residential service entrance equipments comprise a single mounting panel containing several of these pullout switches to serve a corresponding number of load circuits of various types and capacities.

Today, pullout switches, of diiferent capacities, have been standardized as to the external physical size and terminal arrangement utilized. Such standardization minimizes costs of manufacture, stocking and merchandizing. Thus, for example, 60 ampere yand 30 ampere pullout switches are of identical external size and utilize the same terminal arrangement, so that the enclosures, connecting fuses or wires are standard for any combination of components.

However, since the various` bases appear similar, the problem now arises of preventing the coupling of a puller having a fuse capable of passing a relatively high current to Ka base Wired to carry relatively low current.

It would be hazardous, for example, to couple accidentally a puller having a `6() ampere fuse to a base wired to a 30 ampere load, because there would be no proper overload protection for the circuit.

Accordingly, it is a rst object of my invention to provide a pullout switch comprising simple and dependable means for preventing the puller from closing the circuit if it is carrying a 60 ampere fuse when applied to a base intended to serve a 30 ampere load.

2,907,849 Patented Oct. 6, 1959 It is a further object of my invention to provide a puller suitable for use with either 30` ampere or 60 ampere fuses with equal facility.

It is a feature of my invention to accomplish the above objects with only a slight and inexpensive change in the tooling necessary to manufacture the basic product.

In accordance with a rst aspect of my invention, there is provided a pullout switch of the above mentioned type comprising a base portion, a puller portion and characterized by means for preventing the insertion of the puller into the base when the puller is carrying an oversize fuse relative to the load capacity of the circuit served by the pullout switch.

In accordance with another aspect of my invention, l provide a novel fuse clip which is capable of holding alternatively, fuses of two different capacities.

The above and further objects and features of the invention will be more apparent hereinafter wherein reference is made to the accompanying drawings, in which- Fig. 1 is a side cross-sectional view of a pullout switch constructed in accordance with my invention and carrying a suitable fuse for the base of the switch;

Fig. 2 is the same view of the pullout switch, but in this ligure the fuse carried by the puller is too large for the base;

Fig. 3 is a plan view of the base and shows by dot and dash lines the relative sizes of acceptable and unacceptable fuses;

Fig. 4, A and B, are side and front views of my novel fuse clip holding a smaller fuse in one portion thereof; and

Fig. 5, A and B, are the same views of the fuse clip holding a relatively larger fuse in a second portion of the clip.

Referring first to Figs. l, 2 and 3, there is shown a pullout switch comprising essentially a base portion and a puller portion.

The base portion is made of an insulating material such as Bakelite and is: in the form of an open hollow rectangular box, comprising side walls 1, bottom 2 and end walls 3. Along the bottom edges of the respective end walls 3 platforms 4 are provided, preferably integral with the box and molded as part thereof. The platforms 4 provide support for solderless terminal connectors 5, 6, 7 and 8 in a manner to be explained later.

In order to prevent any accidental contacting of the wires after the wires are connected to the respective connectors, pairs of ribs 9 and 10 are provided between adjacent connectors (Fig. 3), perpendicular to the platforms 4 and end walls 3. The pairs of ribs 9, 10 are preferably molded with the box as an integral part thereof, and lend structural support to the box. The lower portions of the ribs, extending below the bottom 2 of the box, serve as footing for mounting the base and is of sufficient height to raise the electrical components oft' the surface on which the base is mounted. Recessed holes 11 and 12 are provided between the pairs of ribs 9 and 10 respectively, to accommodate screws or other means for mounting the base to a wall.

Connected to the terminal connectors 5, 6, 7 and 8 are switch clips 13, 14, 15 and 116 respectively. The switch clips comprise clip portions which underlie suitable openings in the bottom 2 of the box and integral tongue portions attached to the platforms 4 by any suitable means, such as screws or the like (not shown). The tongue portions lit snugly in slots provided in the o body of the connectors to retain the connectors in position. This type of connector is well known and forms no part of this invention.

In accordance with a first aspect of my invention, the base also comprises positive means in the form of projectionsor studs `17, preferably molded asy part thereof,r to prevent the insertion of a puller carrying a fuse having a greater capacity tharivyfmay be carried safely by the base wiring. The speciic location of the studs depends on the relative sizes of the fuses and will be made clear from the discussion which follows hereinafter.

The puller portion of the pullout switch comprises a rectangular cover plate 18 of insulating material which is fdirnensioned to t into the opening of 'the box as shown'in Fig. 1. A handle 19 is pivotally mounted on the outside of the cover plate. On the undensideof the cover plate 18 and rigidly attached ther''eto`,L a-rer four switch blades, two of which are shown atfv20 'and '21. The ends of the blades enter the clip portions of the switch clips when the cover 18 is fully seated as shown in Fig. 1. K)

Fuse clips, two of whichfare shown at Z2 and 23, are provided, preferably integral, withthe Vends of the switch blades underlying the cover. The fuse clips are designed toholdcartridge type fuses. The distancebetween the fuse clips. is determined by the physical size of the fuse, which varies with the current carrying capacity of the fuse. shown in Fig. 1 in relation to a standard type pullout switch box, a 60 ampere fuse in Fig. 2, and the relative size of the two fuses, is shown by dot land dash lines in Fig. y3. Thus, if the box is designed to accommodate a 30 ampere fuse, the studs 17 are separated suficiently to permit only the 30 ampere fuse to passtherebetween. The length of the 60 ampere fuse is greater than the distance between the studs 17 andthus, the studs block the passageof the fuse, as shown in Fig. 2, and prevent the switch blades from contacting the switch clips.

If desired, additional'studs 24 (Fig. 3) may beprovided in'tegral with the sidewalls 1 as further protection against inserting an oversized fuse in the base.

Referring now to Figs. 4 and 5, there is illustrated a fuse clip forming another aspect of my invention. lnstead of diierent and separate fuse clips, 'f1 provide a single clip capable of accommodating fuses of dinerent current carrying capacities. The clip 25 comprises a longer and narrower upper portion 26 adapted to supy port thesinaller fuse amperes), and a shorter and wider lower portion 27 adapted to hold'the larger fuse (.60 amperes). By utilizing such fuse clips, complete standardization is achieved of both the mechanical and electrical portions of the pullout switch.

` It is to be realized that one box may be designed to accommodateeither'two similarly rated fuses, or differently rated fuses by simply providing the studs 17 Von only one 'side of the box.

While I have 'described the principles of my invention in connection with specific modifications thereof, it is to be clearly'understood thatV this description is made by way of example and not las a limitation'to the Vscope of my invention as set forth inthe objects'thereof and in the accompanying claims.

What is claimed is:

1. A pullout switch comprising Va base portion and a'puller portion, said base portion comprising an open rectangular box of insulating material, a line terminal and a load terminal, a pair of switch clips connected respectiv'el'y to each of said terminals, said puller portion comprising a cover plate of insulating'material tting snugly inside saidbox, a handlemounted onVV the outside' surface of said'cover, a of switchblades, each having oneY part xedly mounted to the'underside ofv said cover and a depending Y'part engaging'said switch clips when said cover is inserted in saidbox, a pair of fuse By way of example, a 30 ampere fuse isV i clips connected respectively to said one part of said switch blades, said fuse clips being spaced a iixed distance apart and shaped to hold fuses of different physical sizes, and means for preventing the insertion of the cover when an oversize fuse is carried thereby relative to the load capacity of the circuit served by said pullout switch, comprising a projection on the base of said box extending toward said cover and located to interfere with the passage of the oversize fuse before the switch lades engage said switch clips.

2. The switch according to claim l, wherein said means for preventingthe insertion of said cover comprises a pair of projections extending from the base of said box towards said cover, and spaced apart to permit a fuse of desired size to pass therebetween, an oversize fuse having a length greater than the distance between said projections.

3. A pullout switch comprising a base portion and a puller portion, said base portion comprising an open rectangular box of insulating material, a line terminal and a load terminal, Va pair of switch clips connected respectively to each of said terminals, said puller portion comprising a cover plate of insulating material fitting snugly inside said box, .a handle mounted on the outside surface of said cover, a pair of switch blades, each having one part *xedly mounted to the underside of said cover and a depending part engaging said'switch clip when said cover is inserted in said box, a pair of fuse clips Vspaced a xed distance apart and connected respectively `to said one part of said switch blades, each of said fuse clips comprising a 'iirst part extending closer f towards each other and a second part integral therewith extending further apart, wherebya fuse of shorter length may be inserted in said rst parts and alternatively a fuse of longer length may be inserted in said 'second parts.

4. A pulloutswitch comprising a base portion and a puller portion, said base portion comprising an open rectangular box of insulating material, a line terminal and aloadterminal, a pair of switch'clips connected respectively to each of said terminals, said puller portion comprising a cover plate of insulating material fitting snugly inside said box, a handle mounted on the outside surface of said'cover, a pair of switch blades, each having one part xedly mounted to the underside of said cover and a depending part engaging said switch clips when said cover is inserted in said box, a pair of fuse clips spaced a fixed'distance apart and connected respectively to said one part of said switch blades, each of said 'fuse clips comprising a lfirst part extending closer towards each otherand a second part integral therewith extending further apart, wherebya fuse of shorter length maybe inserted in said iirst parts and alternatively a fuse of'longer length may be'inserted in said second parts, and means for preventing the insertion of the cover when an oversize fuse is carriedthereby'relative to the load` capacity of the circuit served by said pullout switch, said means comprising aprojection on the interior of said box located to interfere 'with the passage of the oversize fuse before the switch' blades engage said switch'clips.

5. The switch according to claim 4, wherein said projection is located on the base of said box extending towards said cover. I

6. The switch 'according to claim 4, wherein said means for preventing the insertion of said cover comprises a pair of projections extending from the baseof said box towards said cover, and spaced apart to permit a fuse of desired size to pass therebetween, an oversize fuse having a length greater than the distance between said projections.

7. A fuse clip adapted to hold alternatively, different size fuses of the cartridge type, comprising a first part in the form of an `inverted truncated triangle with the base thereof constituting the upper'portion of said clip, a second part ldepending from and integral with a porclip and a relatively larger fuse may be held by the cylindrical segmental part of said clip. 

